General design for a door hinges in the prior art merely has the functions for the door to be pivotly jointed and supported on a fixed door frame and the hinge itself does not have the capability to bring the door back to its closed position automaticly after it has opened for a passage. Therefore, in most places such as air-conditioning room and VIP's office has to trouble the person who came in/out to close it by hand in order to keep the door to be closed for privacy and maintaining room temperature. Although, one type of door hinge used on screen door in the early days provided with an inner expansion spring to preform automatic returning function, however, the returning force is created by spring expansion and repeat expansion is tend to cause damage to the spring. Experience in using this type of hinge indicated that a short period of its usage, the hinge will start to making noise when door is operating and followed by gradually lossing of its strength and finally lead to its total failure. In fact, this type of hinge is definitely not suitable to be used on ordinary office/room doors.
Based on the above, the present invention provide a door hinge with automatic returning means which can be widely used on all kinds of doors and windows etc.. The main purpose of this design is to give a further function for automatic returning in addition to a hinge's basic characters as well as to eliminate all the drawbacks which happened on that particular type of hinge used on screen door in early days.
The further object of the present invention is to design a automatic returning device which will achieve the purpose for the door to "open fast and slow to close" by having a buffer spring fitted on the lower portion of driving element.
Additional, a butterfly screw is located on the outer sleeve which can be screwed in transversely to urge against the driving element to disable the rotation of both male and female hinge members when a door's fixed position is desired for temporary purposes.